Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland

Abstract

The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72–87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29–96% of the inorganic and 4–81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the importance of small scale physical processes within ponds to material flux of the wetland.

Zooplankton Dynamics in the Cache Slough Complex of the Upper San Francisco Estuary

“…The only previously published studies of zooplankton fluxes in the Delta have been at Liberty Island and surrounding wetlands in the CSC (Lehman et al 2010(Lehman et al , 2015. Discrete samples were taken at four stations for chlorophyll concentration (16 occasions) and zooplankton abundance (6 occasions) in 2004-2005, and water flow was calculated from tidal fluctuations in surface elevation and area (Lehman et al 2010).…”

Characterizing macroinvertebrate community composition and abundance in freshwater tidal wetlands of the Sacramento-San Joaquin Delta

“…This site was particularly important for Platyhelminthes and Hemiptera (Table 5b). Liberty Island also has a much larger area of open water adjacent to our sampling sites than the other two regions, with the potential for increased wind-waves and phytoplankton productivity, which may impact invertebrate abundance [71]. Our observed regional differences may be due to habitat factors not included in our models, such as water velocity, water source, substrate type, and average depth.…”

Preliminary Analysis of C Sequestration Potential of Blue Carbon Ecosystems on Chinese Coastal Zone

“…蓝碳生态系统碳汇潜力的形成, 主要得益于相对 高的净初级生产力和缓慢的有机质分解 [23] , 同时受潮 汐影响产生的水平碳交换也是碳汇的重要构成要 素 [24,25] , 后者也是蓝碳汇估算中的主要误差源和挑战 之一. 由于土壤水分饱和、通气性差、地温低且变幅 小等各种环境因素的限制, 蓝碳生态系统的碳汇通常 以有机碳在土壤或沉积物中的积累为主要特征 [26] , 但 随着全球气候变化以及滩涂围垦和土地利用的变化, 土壤无机碳可能成为蓝碳生态系统碳汇潜力变化的重 要影响要素.…”